1. Field of the Invention
This invention relates generally to the field of pipe fitting and more particularly to an apparatus and method for the squaring of a pipe flange relative to an adjoining pipe in preparation for welding.
2. General Background
When preparing to weld a pipe flange to the end of a pipe, it is necessary to align the diameters of the neck portion of the flange and the pipe to which the flange is to be welded. In most cases the ends of the flange neck portion and the pipe have been prepared with an acute bevel. The two ends are brought into close proximity and held in place by a series of clamps and spacers located around the periphery of the pipe outer diameter in such a manner as to leave the joint unobstructed for welding. Shims and the like are provided in association with the clamps for adjustably aligning the flange neck portion with the pipe diameter. To insure that the face of the flange is in fact truly perpendicular to the pipe diameter, a large framing square is used as reference. By placing one leg of the square along the face of the flange and using a tape measure to determine the distance from the opposite leg of the square suspended above the pipe's outer diameter and repeating this procedure at various points around the diameter of the pipe, a mean average can be ascertained. The clamp spacers may then be adjusted to true the flange face with the pipe and the process repeated until a reasonably true perpendicular is achieved.
Methods have been devised for squaring the ends of pipe, such as is disclosed by Paviak in U.S. Pat. No. 5,231,766. Squaring tools for use by pipe fitters have been developed for determining the angle for joining and leveling pipe, etc., as disclosed by Howard in U.S. Pat. No. 4,914,825. Tools have also been developed for determining the parallel spaced apart relationship of pipe joints and the like with a caliper-like instrument, such as is disclosed by Moran in U.S. Pat. No. 4,380,872. A number of apparatus have also been devised for aligning the flanges of two adjoining pipes, such as is disclosed by VanMeter in U.S. Pat. No. 4,662,055. However, the art does not seem to provide an easy and efficient tool for determining perpendicularly of the face of a pipe flange relative to the outer diameter of the pipe being attached.